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Biomedical subjects

D A Wilson

Publications and source records attributed to D A Wilson.

At least 181 records · Page 10Linked to original sources
PubMed1984

A comparison of the postnatal development of post-activation potentiation in the neocortex and dentate gyrus of the rat.

The postnatal development of short-term potentiation (STP) and long-term potentiation (LTP) was examined in the neocortex and dentate gyrus of rats aged 7 days to adult. STP and LTP of the transcallosal response in the neocortex could not be demonstrated until the third postnatal week. STP and LTP of the perforant path-dentate response could not be demonstrated until the second postnatal week. In both cases, STP appeared several days before LTP. Structural and neurochemical correlates of STP/LTP development, and their implications for possible STP/LTP mechanisms, are discussed.

Aging↗
PubMed1984

Pyloric stenosis: diagnosis by real time sonography, the pyloric muscle length method.

Real time sonography was performed for identification of pyloric stenosis in 100 infants referred for vomiting. In nine patients, imaging did not identify the pylorus. One of nine had pyloric stenosis. In 91 imaged patients, 40 had pyloric stenosis and 51 did not. Each imaged patient had determinations of the three described diagnostic pyloric muscle measurements: pyloric muscle diameter, pyloric muscle thickness, and pyloric muscle length. The determination of pyloric muscle length was the most accurate (97.8%); it had two false negatives, but no false positive results. Erroneous surgery was thereby avoided. We conclude that real time sonographic determination of pyloric stenosis is reliable and practical, and that pyloric muscle length determination is the most accurate of the currently available techniques.

Humans↗
PubMed1984

An evaluation of diagnostic techniques utilized in the initial workup of pediatric patients with acute lymphocytic leukemia.

The records of 32 pediatric patients with acute lymphocytic leukemia (ALL) were reviewed to evaluate the role of various diagnostic techniques used to assess the extent of extramedullary disease. Our findings indicate that adequate screening for hepatosplenomegaly is obtained by clinical assessment and for bone and renal involvement by bone scintigraphy including concomitant renal imaging. We recommend that radiographs be restricted to scintigraphically abnormal areas and/or sites of bone pain. Liver-spleen scintigraphy, gallium studies, intravenous pyelography, and ultrasound studies of the abdomen and pelvis should be utilized only to answer specific clinical questions. Evaluation in this manner reduces both radiation exposure and patient expense, while it adequately defines the extent of disease in these organs.

Bone and Bones↗
PubMed1984

Histoplasmosis of the adrenal glands studied by CT.

Computed tomography (CT) of the adrenal glands was performed on seven patients who had histologically proved disseminated histoplasmosis. All seven patients showed some degree of adrenal gland abnormality. The range of CT findings included minimal enlargement with faint flecks of calcium, moderate enlargement with focal low attenuation nodules, and massive enlargement with large areas of necrosis or dense calcification. The changes in each patient were bilateral and symmetrical. Adrenal gland shape was usually preserved. Findings of percutaneous adrenal biopsy, which was performed under CT guidance, made the diagnosis in one patient. Five of seven patients had adrenal insufficiency. We conclude that the diagnosis of disseminated histoplasmosis should be considered in any patient who has bilateral adrenal gland enlargement and who resides in an endemic area, especially if there is evidence of adrenal insufficiency, and that CT is superb for the assessment of adrenal gland morphology in this disease, and CT-directed biopsy is the recommended method of confirming the diagnosis in difficult cases.

Adrenal Gland Diseases↗
PubMed1983

Leiomyoma presenting as prolonged fever, anemia, and thrombocytosis.

The manifestations of leiomyoma of the large bowel in a 2-year-old boy included prolonged fever, anemia, and thrombocytosis. This parallels the previously reported case in an adult. Awareness of these features may suggest the diagnosis in future patients, and thereby offer opportunities to study the pathogenesis of these abnormalities before surgery.

Anemia↗
PubMed1983

The postnatal development of post-activation potentiation in the rat neocortex.

The postnatal development of short-term potentiation (STP) and long-term potentiation (LTP) of the transcallosal response (TCR) was examined in anesthetized rats, aged 7 days (PN7) to adult (greater than or equal to PN180). Stimulation of callosal fibers produced a biphasic, positive-negative TCR recorded at the surface of the anterior neocortex in all age groups. The TCR showed a decrease in threshold, latency and halfwidth, and an increase in peak amplitude with age. High frequency callosal stimulation produced marked STP and LTP of the mature TCR. STP in young animals, however, could not be reliably detected until after PN16. LTP was not detected until PN18. STP and LTP approached adult levels rapidly after their initial appearance. The correlations between STP/LTP onset and development and known structural developments such as initial synaptogenesis, spine formation and myelinogenesis were not particularly strong. The implications of these results for specific hypotheses of STP/LTP mechanisms were discussed.

Animals↗
PubMed1982

Comparison of Indium-111 platelet scintigraphy and two-dimensional echocardiography in the diagnosis of left ventricular thrombi.

In a study comparing indium-111 platelet scintigraphy and two-dimensional echocardiography as methods of identifying left ventricular thrombi, the results obtained with both techniques were verified at surgery or autopsy in 53 patients--34 with left ventricular aneurysms, and 19 with mitral-valve disease. Left ventricular thrombi were found at surgery or autopsy in 14 of the patients with aneurysms and in none of those with mitral-valve disease. Thirteen of 53 echocardiograms (25 per cent) were technically inadequate and excluded from the analysis. In the group with aneurysms, the sensitivity of scintigraphy in detecting thrombi was 71 per cent, and that of echocardiography was 77 per cent. The specificity of scintigraphy was 100 per cent, and that of echocardiography was 93 per cent. We conclude that indium-111 platelet scintigraphy and two-dimensional echocardiography have useful and complementary roles in the detection of left ventricular thrombi. Both these noninvasive techniques can be used to monitor therapy.

Adult↗
PubMed1982

Ultrasound screening for abdominal masses in the neonatal period.

A total of 36 patients, 6 weeks of age or younger, were examined by ultrasound for a suspected abdominal mass during the four-year period between May 1977 and May 1981. A total of 46 abdominal masses were detected in 29 patients. The ultrasound diagnosis was correct or directly contributory to the final diagnosis in 96% (43/45) of the cases. The diagnosis was incorrect or misleading in only 4% (2/45) of the cases. When no pathologic mass was demonstrated by ultrasound, this observation was confirmed to be correct in every case. The study was safe, reliable, and quickly performed with no discomfort for the patient. Ultrasound should replace the intravenous urogram as the initial screening procedure for neonates with a suspected abdominal mass.

Abdomen↗
PubMed1982

High-resolution ultrasound evaluation of experimental brain abscess evolution: comparison with computed tomography and neuropathology.

Computed tomographic (CT) and high-resolution ultrasound (HRUS) imaging of experimental brain abscess were correlated with neuropathologic findings in nine mongrel dogs. The HRUS scan was more sensitive to different histologic features than the CT scan but both accurately delineated the evolution of the experimental brain abscess. All stages of abscess evolution were characterized by an appearance of an echogenic rim with a hypoechoic center. In the early stages the echogenicity of the abscess was related primarily to marked cellular infiltration, while in the late stages extensive collagen deposition correlated closely with the echo pattern. The size of the abscess in the cerebritis stages appeared smaller on the HRUS scan than on the CT scan because the latter modality detected the extensive cerebritis around the developing necrotic center whereas the HRUS scan did not. This discrepancy disappeared in the capsule stages. The HRUS scan provided a more accurate depiction of the neuropathologic characteristics of the necrotic than did the CT scan. Healing of the abscess, indicated by a decrease in size of the hypoechoic center, was accurately detected by the HRUS scan.

Animals↗
PubMed1982

Hearing-aid use and available aid ranges.

The assertion that a wide range of hearing aids is necessary in auditory rehabilitation has frequently been made, but little evidence has been offered as support. Further, little explanation has been offered as to the constitution of an adequate range of aids, nor what determines the adequacy. Comparisons of use rates of two large populations of people, one fitted from a wide range of aids and the other from a narrow range, provides some information on the relationship between extent of the aid range available and the results of fitting. The conclusion is reached that fitting methods and procedures appear to be more significant than aid range in ensuring that hearing aids are used consistently.

Adolescent↗
PubMed1982

Noninvasive evaluation of hemophilic pseudotumor of the pelvis.

Hemophilic pseudotumors are a rare complication of chronic bleeding disorders. Invasive diagnostic procedures such as angiography, needle biopsy, or laparotomy carry a high risk in this group. Computerized tomography (CT) and ultrasound are safe alternative methods of evaluation. We report the computerized tomography and ultrasound characteristics of one such pelvic lesions.

Adult↗